Background Suicidal behavior is an important global health problem affecting also significant others. Both genetic and environmental influences play an important role in the development of suicidal behavior. There is a need of interventions for family and friends after a suicide attempt. The aim of this thesis was to assess the impact of family history of suicide (FHS) and early life adversity (ELA) on severity of suicidal behavior and on level of interpersonal problems in suicide attempters. Furthermore it aimed to evaluate a DBT-based skills training program, Family Connections (FC), for relatives and friends of suicide attempters. Methods Studies I and II included 181 suicide attempters. FHS was assessed with the Karolinska Self-Harm History Interview or in patient records. ELA was assessed with the Karolinska Interpersonal Violence Scale (KIVS) measuring exposure to interpersonal violence in childhood. Suicide intent was measured with the Freeman scale. Interpersonal problems were assessed with the Inventory of Interpersonal Problems (IIP). Study III, a pilot study evaluating the effect of FC for family members of suicide attempters, included 13 participants who completed the program with pre- and post-questionnaires. The experience of burden was assessed with the Burden Assessment Scale (BAS), general wellbeing with Brief Symptom Inventory (BSI) and level of depression was assessed with Beck Depression Inventory (BDI). The Swedish scale Questions About Family Members (QAFM) was used to explore the quality of the participants’ relationship with the patient and the Quality of Life Inventory (QOLI) was used to measure satisfaction with life situation. Study IV included 132 family members, and investigated the feasibility and preliminary efficacy of FC in psychiatric care. Participants were assessed pre- and post-intervention with the following self-report questionnaires: BAS, QAFM and Five Facet Mindfulness Questionnaire. Results Male suicide attempters with FHS made more serious and well planned suicide attempts and had higher suicide risk. FHS and exposure to interpersonal violence as a child were independent predictors of suicide in male suicide attempters. Regarding interpersonal problems, suicide attempters with FHS had significantly more often an intrusive personal style, indicating that they might have an impaired ability to create stable, long-lasting relationships. In the pilot study the participants reported a significant reduction in burden, an improved psychic health and an improvement in the relationship with the patient after completing FC. In the fourth study, FC showed to be feasible and effectively implemented in a psychiatric outpatient services clinic. Regarding burden, results were in line with the pilot study, with a significant reduction in all subscales in BAS. Conclusions High-risk patients call for a consideration of both ELA and FHS in clinical suicide risk assessment. In suicide attempters at biological risk, suicide might be prevented with the early recognition of environmental risks. Further, the interpersonal problems associated with FHS may cause difficulties for suicide attempters to accept or benefit from treatment, and caregivers should take into account the characteristics of the suicide attempter´s interpersonal functioning. The results from the pilot study provide support for the need and importance of an educational program addressed specifically to family members of suicide attempters. Preliminary results support the feasibility and potential value of an implementation of FC in psychiatric open care clinics.